Propeller



May-29,1923.

W. R. MCDONALD' PROPELLER Filed'May 4, 1922 2 Sheets-sheet a III-III..

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Patented May 29, 1923 narran stairs-s rasant .e are, fr.

PROPEIJLER.

Application filed May 4,

improvements in a propeller, and has particular relation to a propeller especially designed for use on aeroplanes.

One object of the invention is to provide a propeller of the character described having a plurality of propeller blades arranged in series.

Another object of the invention is to provide a propeller whose blades are detachably secured to the hub.

A still further feature of the invention resides in the provision of a specially designed hub to which the propellerl b lades are attached, and which may be easily and quickly assembled or taken apart.v

With the above and other objects in view the invention has particular relation to certain novel features of construction, arrangement of parts and use, an example of which is given in this specification and illustrated in the accompanying drawings,V wherein Figure l shows a plan view of the propeller attached to the front end of an aeroplane. l

Figure 2 shows an'end view of the propeller.

Figure Sshows a front view.

Figure 4 shows an enlarged fragmentary horizontal sectional view, and,

Figure 5 shows an enlarged fragmentary rear view. i

In the drawings the numeral l designates the aeroplane having the forwardly projecting propeller shaft 2, the forward end of which carries the hubl 8. This hub is formed of the cylindrical drum 4 which is splined on the shaft 2, and the shell 5 which is secured on said drum. This shell is formed of two sections, as shown in Figure 5. The inner ends of these sections have the clamping flanges 6, 6 which fit over and interlock with the inner end of the drum 4, and at their other ends the drum and 1922. Serial N0. 558,490.v

shell are keyed together by means of the keys 7, 7, and an vend cap 8 is then screwed onto the forward ends of the sections 5 of the shell. Each section 5 has a plurality of correspondingly spiraled dove tailed grooves 9, forming anchors for the inner ends of the blades 10. The adjacent 'ends of these bladesare formed to conform to, and tit in said grooves, and the blades are thereby vanchored to the respective sections 5, 5 of the shell before the hubis assembled. The outer ends of the blades converge and are secured together by means of the end clamps ll.

The blades on either side are provided with the braces l2 to strengthen and give them rigidity.

vTwo opposing series of blades have been illustrated, but three or four series may be employed, if desired, as indicated by dotted lines in Figure 3. I

What l claim is 1. A propeller including a hub, and a plurality of series of propeller blades anchored thereto, and radiating therefrom, said hub having spiral mortises and the adjoining ends of the blades having tenons which Iit in said mortises.

2. A propeller including a central hub, a plurality of series of propeller blades WILLIAM n. Menonarn, or nons'ron', TEXAS.

radiating therefrom, spiraled .dovetti-Hed'.

grooves in the hub and tenons into which the adjacent ends of the blades are formed, said tenons fitting in said grooves, said blades converging and their outer ends being secured together. v

3. A propeller including a vhub formed of a cylindrical drum, a shell formed of two sections surrounding the drumn said sections at one end having clamping flanges which fit over and interlock with one end of the drum, keys securing the other ends of said shell sections to the drum and a cap screwed over the last mentioned end of the hub.

4. A propeller including a hub formed of a cylindrical drum, a shell formed of two sections surrounding the drum, said sections at one end having clamping flanges which tit over and interlock with one end of the drum, keys securing the other ends of said shell sections to the drum, and a cap screwed over the last mentioned end name to this specification in the presence of the hub, and a plurality of series of pro, of two subscribing witnesses. peller blades radiating from the hub, said blades of each series converging outwardly WILLIAM' R' MCDONLD 5 and having their outer ends secured to- Witnesses:

gether. W. H. DUNLAY,

In testimony whereo I have signed my E. V. HARDWAY. 

